BACKGROUND: The etiology of esophageal atresia is poorly understood. The incidence of some congenital malformations is increased in children of mothers with diabetes, but the role of maternal diabetes in esophageal atresia development in the infant is unknown. We hypothesized that maternal diabetes increases the risk of esophageal atresia in the infant.METHODS: A population-based, matched case-control study, nested within a cohort of neonates born in Sweden in January 1, 1982 through December 31, 2007, was undertaken. Conditional logistic regression was used to calculate relative risks, expressed as odds ratios with 95% confidence intervals. Adjustment for confounding was made through matching and by multivariable regression.RESULTS: Among 2,625,436 newborn infants in the study cohort, there were 780 cases of esophageal atresia, and 7,800 infants were matched and randomly selected as controls. Exposure to preexisting or gestational diabetes was more frequent in the mothers of the case group (n = 18; 2.3%) than in those of the control group (n = 103; 1.3%). The adjusted risk of esophageal atresia was 70 % higher among infants of women with diabetes than among women without diabetes (odds ratio, 1.7; 95% confidence interval, 1.0-2.9).CONCLUSIONS: Maternal diabetes might increase the risk of esophageal atresia in the child.